Preheat the oven to 350°F (180°C).

Melt the butter and chocolate together. Add the sugar, then the eggs, beaten.

Stir in the almond flour and vanilla extract. Mix well, then add the rum and mix again.

Spread the filling over one sheet of puff pastry, leaving a 1-inch (3 cm) border all around (don’t forget to add the traditional fève if you have one!). Cover with the second sheet of puff pastry, pressing the edges together with your fingers and folding the bottom edge over the top to seal. Make sure the filling can’t escape.

Use a knife to create decorative patterns on your galette as you like, then gently brush the top with the beaten egg yolk (you can dilute it with almond milk if you prefer), using a pastry brush or your fingers.

Bake for 35–45 minutes, depending on your oven. Keep an eye on it towards the end of baking.